It's a strong causal claim: Giving kids sips of beer turns them into teenage drunks. Did the journalist get it right? Here are some quotes from the story, posted in the food website Munchies:
Those innocent tastes of Chianti at the Thanksgiving dinner table could morph your child from a sweet, sober cherub into a bleary-eyed teenage booze-guzzling ne'er-do-well.
New research in the Journal of Studies on Alcohol and Drugs has found that children who sip alcohol as youngsters have an increased likelihood of becoming drinkers by the time they reach high school. In a long-term study by Brown University of 561 students in Rhode Island, researchers found that those who had tried even small sips were a whopping five times more likely to have tried a whole beer or cocktail by the time they reached ninth grade, and four times more likely to have gotten rip-roaring drunk.
a) What keywords in this quote indicate that the journalist is making a causal claim?
b) What were the two variables studied by the researchers? Explain whether whether you think each one was measured or manipulated.
c) What kind of study is this claim apparently based upon--correlational or experimental?
d) Given the study's design, is the causal claim appropriate? Apply the three causal criteria.
In an interview with Munchies, the lead researcher, Kristina Jackson, mentions several possible third variables for the association:
But Jackson also believes that other factors correlate with these numbers, in addition to the "early sipper" factor. Parents' drinking habits, a family history of alcoholism, and general personality and behavioral characteristics also have strong impacts on the boozy worldviews of children and teenagers.
e) Chapter 9 readers: Do you see any evidence that the researchers controlled for these potential internal validity problems in their analyses? You might have to hunt down the original journal article to find out.
f) The journalist made a dramatic point about the statistic about kids who'd sipped beer "being four times more likely to have gotten rip-roaring drunk." Which of the four big validities is this statement about?
Even though the journalist's causal claim is probably not justified, adolescent substance use is a serious issue. The journalist supplemented the story with several frequency claims. You might be interested in some of these statistics.
Roughly 30 percent of the students said that they had tasted alcohol when in sixth grade..., mostly due to exposure from their parents while at a party, on vacation, or in other special circumstances. Of that group (the "early sippers"), 26 percent reported having consumed a full alcoholic drink by ninth grade, while only 6 percent of non-early-sippers had experienced the pleasures of an ice-cold Natural Ice or homemade Screwdriver. And at that same age (roughly 14-15 years old), 9 percent of early sippers had gotten totally trashed, while only 2 percent of those with less-loose parents had.